Heat exchanger



' All8- 19, 1958 J. w. JAcQBs 2,848,200

HEAT EXCHANGER l Filed NOV. 26, 1954 2 SheebS-Shet 1 y@yy@MMQMHEMMWMW ff yMMMMMMQMQEmm@ H.@MMQMQWwww? Liszt-n n af. @www i :naman-.mz

I. e n@ www M M @www INVENToR. James W Jacobs His Affarney Aug. 19, 1958 Filed Nov. 26. 1954' J. W. JACOBS HEAT EXCHANGER 2 Sheets-Sheet 2 INVENToR. James W. Jacobs His Attorney United States Patent C HEAT EXCHANGER James W. Jacobs, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application November 26, 1954, Serial No. 471,306

1 Claim. (Cl. 257-255) 'I'his invention relates to refrigerating apparatus and more particularly to an improved heat exchanger construction.

It is an object of this invention to provide a multiple passage heat exchanger having a plurality of relatively at conduits bent into serpentine shape and connected so as to provide two parallel paths for the uid ilowing through the heat exchanger.

Still another object of this invention is to provide a heat exchanger having a pair of at walled conduits bent into serpentine shape and interlaced with one another.

Still another object of this invention is to provide a heat exchanger which may be manufactured at low cost and which affords a minimum amount of restriction to ow of fluid within the passages of the heat exchanger unit.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of the invention is clearly shown.

In the drawings:

Figure 1 is a perspective view showing a preferred embodiment of the invention;

Figure 2 is a developed planned view showing the configuration of one of the conduits used in constructing the heat exchanger shown in Figure 1;

Figure 3 is a fragmentary sectional view showing the construction at the inlet to one of the conduits;

Figure 4 is a fragmentary sectional View taken substantially on line 4-4 of Figure 2;

Figure 5 is a fragmentary sectional view taken on line 5-5 of Figure 2; and

Figure 6 is a sectional view taken substantially on line 6 6 of Figure 1.

Referring now to the drawings wherein a preferred embodiment of the invention has been shown, reference numerals 10 and 12 generally designate a pair of serpentine conduits which are relatively flat in cross section and which have been formed by roll bonding relatively long and narrow strips of metal together so as to form conduits of the desired length and conguration. Each of the conduits is formed by roll bonding two strips of aluminum or the like together with a stop weld material between the sheets in the form of a predetermined pattern so as to form internal passage means. After the sheets have been roll bonded, fluid is inserted between the sheets so as to separate or dilate the sheets throughout the areas deiined by the stop weld material. For a more complete description of the method and materials used in making the individual conduits, reference is hereby made to copending application S. N. 289,729, led May 24, 1952, now Patent No. 2,740,188.

Each conduit is provided with cut-away portions 14 (see Figure 2) at each of the points where the strip is later bent to form a return bend. By virtue of the fact that the return bend portions 15 of the strips are of reduced Width it is possible to form two diterent rela- ICC tively flat conduits into serpentine shape and to interlace them as shown in Figure 1.

Corrugated fin portions 16 are placed between the adjacent straight portions of the conduits and are brazed or otherwise secured to the side walls of the conduits so as to form a rigid one piece construction in which the ns are arranged in direct physical contact with the side walls of the uid passages provided in the conduits 10 and 12. In order to provide for even distribution of the uid flowing through the conduits, the pattern of the stop weld material in each of the conduits 10 and 12 includes a plurality of elongated welded areas 18 arranged adjacent the inlets 20 to each of the conduits and a plurality of staggered welded areas 22 arranged throughout the straight portions of each of the conduits as shown in Figures 1 and 2.

One of the problems in forming heat exchangers having integral return bends is that of preventing undue restriction to the ow of refrigerant or other uid at the return bends. The bending operation has a tendency to restrict the size of the uid passage of a flat walled tube at each return bend and in order to help overcome this tendency a strip of stop weld material is used to form a strengthening rib 24 which extends substantially the full length of the return bend. It has been found that the above arrangement adds rigidity to the return bend and reduces the tendency of the tube to collapse during the bending operation.

In order to minimize the restriction to the flow of iluid through the heat exchanger, the two conduits 10 and 12, are connected in parallel ow relationship to the main supply conduit 26 by means of adapters 28 and 30, each of which includes a semi-circular portion at the one end for insertion into the supply conduit 26 and each of which has its other end connected to one of the heat exchanger conduit elements 10 or 12. The outlets of the conduits 10 and 12 are similarly joined to a common outlet line 32 by means of adapters 34 and 36 which correspond in construction and arrangement to the corresponding elements 28 and 30 described herein above.

It will be noted that the inlet and outlet lines connect to the central portion of the ends of the conduits 10 and 12 whereby both conduits may be made alike.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claim which follows.

What is claimed is as follows:

In a heat exchange unit of the type having a plurality of parallel fluid passages, a first relatively at fluid conduit having a plurality of parallel portions connected by integrally formed relatively at return bend portions of reduced width, a second relatively at uid conduit having a plurality of parallel portions interlaced with the parallel portions of said rst conduit and connected by integrally formed relatively fiat return bend portions of reduced width arranged in staggered relationship to the return bend portions of said first conduit, and header means connected to said rst and second conduits for supplying uid to said conduits in parallel.

References Cited in the le of this patent UNITED STATES PATENTS 1,936,284 Bergman Nov. 21, 1933 1,990,752 Ragsdale ---s Feb. 12, 1935 2,164,005 Booth June 27, 1939 2,482,951 Vonk Sept. 27, 1949 FOREIGN PATENTS 5,803 France Nov. 21, 1906 (Addition to No. 361,558) 

